I ended up skilling elemental magic up in an old Swamp biome I had cleared of iron a long time ago. I still had a portal there and remembered a circle of stones that had 2 draugr spawners and 1 skeleton spawner.

I've killed so, so many skeletons and draugr and got my elemental magic into the high 40s. I also had tons of entrails and bone fragments to toss into the obliterator for extra coal.

If I had known the greydwarf nests were immune to frost damage and you can shoot it with the frost staff forever I might have done that instead. Either way, it was pretty damn boring but for sure way faster at leveling the skill than just running around like you normally would.